Stream操作的叠加,通过ReferencePipeline将各个操作组装成一个调用链,通过Sink接口定义每个操作之间的关系。 Stream并行处理,通过parallelStream()方法或parallel()方法将串行流转换为并行流,通过ForkJoinPool框架实现数据的分割和合并。 7、Reactive技术 性能优化之reactive技术是指一种面向数据流和事件的异步编程范式,可以提高...
int threadNumber = 8; ForkJoinPool pool = new ForkJoinPool(threadNumber); // force the creation of all worker threads pool.invokeAll(Collections.nCopies(threadNumber*2, () -> { Thread.sleep(500); return ""; })); int oldNum = pool.getPoolSize(); System.out.println(oldNum+" threads...
Apache Commons Lang 3 中的org.apache.commons.lang3.concurrent.BasicThreadFactory。 ThreadFactorythreadFactory=newBasicThreadFactory.Builder().namingPattern("computation-thread-%d").build();ExecutorServiceexecutorService=Executors.newFixedThreadPool(numberOfThreads,threadFactory); 虽然ForkJoinPool没有使用ThreadFactory...
.build(); ExecutorService executorService = Executors.newFixedThreadPool(numberOfThreads, threadFactory); 尽管ForkJoinPool不使用ThreadFactory接口,但也支持对线程的重命名: ForkJoinPool.ForkJoinWorkerThreadFactory forkJoinThreadFactory = pool -> { ForkJoinWorkerThread thread = ForkJoinPool.defaultForkJoinWorker...
import java.util.concurrent.ForkJoinPool; import java.util.concurrent.RecursiveTask; To use the library, first create a ForkJoinPool object. You should do this only once -- there is no good reason to have more than one pool in your program. It is the job of the ...
(1) ThreadLocal的代价 没有魔术 ,开放地址法的HashMap Netty的 FastThreadLocal, index原子自增的数组 volatile的代价 Happen Before,保证可见性 每次访问比同步块开销小 ,但也不可忽视 可存到临时变量使用 ,直到可见性时才再次访问它 并发的其它话题 (2) ForkJoinPool的其他优势: 每线程独立任务队列 Netty的...
public static void main(String[] args) throws InterruptedException, ExecutionException { ExecutorService es = ForkJoinPool.commonPool(); Future<Void> c1 = es.submit(() -> { System.out.println("Start CF 1"); Thread.sleep(1000); System.out.println(1); return null; }); Future<Void...
ForkJoin pool does have the "managed blocking" goo to manage a user-configured minimum concurrency level, but it doesn't seem used enough for a library to assume it will solve any problems. It's also unclear what sort of impact it has on performance. We realized very early we couldn't...
使用join(inner join或left join)时,小表在前,大表在后,重复关联键少的表放在前面可以提高join的效率。 4.数据库服务器配置优化:内存、连接池 5.分库分表 34. redis的常用数据结构有哪些? redis是K-V存储,K是字符串,V有多种数据类型。 1.string:简单的key-value类型,一般用在计数场景,比如用户访问次数、...
JDK-8078490 core-libs java.util.concurrent Missed submissions in ForkJoinPool JDK-8080623 core-libs java.util.concurrent CPU overhead in FJ due to spinning in awaitWork JDK-8085978 core-libs java.util.concurrent LinkedTransferQueue<T>.spliterator can report LTQ.Node object, not T ...